High-Risk Tunnel Construction Technology-Research and Practice of Energy Release and Pressure Reduction Technology for High Pressure Watery Karst Tunnel

摘要

In tunnel construction, adverse geological conditions such as lava cave, faultage, high ground stress and harmful gas are often encountered. In karst regions, large high pressure watery filling lava caves bring about extremely high risks to tunnel construction. It is difficult to guarantee safety in construction by dealing with high pressure watery filling lava caves with grouting method. In the practice of YichangWanzhou Railway, an "energy release and pressure reduction method" is proposed, which has been applied successfully in four HP watery filling lava cave tunnels, including Yunwushan Tunnel. In this paper, Yun-wushan Tunnel is taken as an example for the discussions about the concept, contents, applicable conditions, opportunities and construction procedures of "energy release and pressure reduction method".